Improvement in fan-blowers



G.'C. HAWKNS.

. .Fan-Blowers.

N0.l48,951 Patented March 24, 1874.

UNITED STATES;

PATENT OEFICE.

GARDNER O. HAVKINS, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN FAN-BLowE'Rs.

Specification forming part of Letters Patent No. 148,951, dated March 24, 1874; application filed December 29, 1873.

To all whom it may concern:

Be it known that I, GARDNER G.HAwK1Ns, of Boston, in the county of Suiolk and State of Massachusetts, have invented certain new and useful Improvements in Fan-Blowers, of which the following is a specication:

My invention relates to the method of constructing the parts of a fan-blower, and to their form and arrangement, so that the greatest effective work may be obtained from them, the whole being so arranged that the least possible resistance is offered to the flow of the air.

To obtain the best economical effect from a fan-blower, other things being' equal, it is necessary to give a rapid circular motion to a volume of air, so that the centrifugal force may be called into action. A body of air thus subjected should be left as nearly free as possible 5 but, to utilize it, it must be subjected to certain' conditions, which depend upon the use to be made of the blower: First, if the blower is to be used as a condenser-that is, to obtain a pressure-so that the air may be used to urge a fire, furnish fresh air to a room or apartment, &c., then the air, as it leaves the instrument, must be conducted into a suitable conduit, which, of necessity, must offer back pressure, and lessen, to a certain extent, the amount of air delivered. The amount of this back pressure will be lessened by the atmospheric pressure fifteen pounds to the inch at the inlet of the blower-that is, supposing that the inlet is so arranged that there is nothing to prevent the free owof air to the interior of the blower.

To construct a blower in such a manner as to offer the least possible resistance to the iniiowing air is one of the objects of my invention, and I obtain this by constructing the fans so that they, and consequently their inclosing disks, shall overhang or project beyond the radial or shaft-connecting frame of the machine. In machines of ordinary construction the radial frames are in, or nearly in, the plane of the disks, so that by their rapid revolution, they prevent the free ilow of air to the interior. Thus a partial vacuum is formed inside of the blower, and the force of the external atmosphere acts against the effect of the centrifugal force, the counterbalancing eifect of the presswhen the blower is to be used as an exhaust.'

Figure l is a perspective view of my invention. Fig. 2 1s a diametric section of the same.

Fig. 3 is a plan of one of the radial frames..

Fig. 4 shows one of the fans and its connections with the shaft.

In the drawings I have only shown the moving parts of the blower, as it is to that part alone that my present invention relates.

F represents the shaft of the blower. Upon this shaft I form two collars or shoulders, F', Figs. 2 and 4, these collars being solid parts of the shaft, and serve as flanges to which the fan-supporting frames are to be bolted.` In. Fig. 3 I show one of these fansupporting frames, which consists of a ring or hub, A, which is to be bolted to the collars F', as shown in Fig. 2. From the ring A radial arms B Bl B2 B3 extend, and terminate in a ring, C. This ring O constitutes the base upon which my fan-supporters are formed. The fan-supports proper D D', &c., project tangentially, and are strengthened by braces E E', Snc., as shown in Fig. 3. The object of this construction is to obtain strength with lightness, and offer as little obstruction to the iiow of air as possible.-

The radial frames, as above described, are made fast to the shaft F by bolts, as shown in Fig. 2.

The fans K are perfectly lat, and formed as shown in Fig. 4. These fans are riveted to the arms D so that each forms a tangential plane. (See Fig. l.) The edges of these fans form the only support of the coned disks H' H', as shown in Figs. 1, 2, and 4. These disks each have a large central opening for the inflowing air. The outer edge of each of Ythese disks is re-enforced by a ring, B, Figs..1 and 2, which gives it stability, and also serves to 2 meen forni-a true edge for tting the opening in the outer case and making the same air-tight, or. nearly so. The coned easings H H overhang the supporting-frames, as shown7 so that there is L free passage for the inowin g air7 as shown in Figs. l and 2.

I claim as my inventionl. In a fan-blower, the radial frame A G, when the sanne is made with larms B B1, 85o., ring C, and t( ngential supporting-arms D D7 &o., braced by stays E E', &e., all substantially'as described7 and for the purpose set forth.

Y set forth.

GARDNER C. HAWKIN S.

Witnesses WILLIAM EDsoN, FRANK G. PARKER.. 

